ATMOSPHERE: Flashcards
ATMOSPHERE:
The layer of gases that surrounds the Earth.
The atmosphere consists of four layers
thermosphere, mesosphere ,stratosphere
and the troposphere
Thermosphere:
the layer of the atmosphere furthest from the Earth
Thermosphere absorbs the harmful
X-rays and ultra-violet rays hence the high temperatures and
also increase with distance from the surface
Mesosphere:
3rd layer above the Earth surface
Mesosphere layer prevents
dust and rocks from space from entering the lower layers
Stratosphere:
2 nd Layer above the surface
Stratosphere Layer contains a layer
of Ozone gas that absorbs the ultraviolet rays from the sun
Troposphere:
Layer closest to the Earth’s surface
Troposphere contains
most of the air of the atmosphere , all the essential gases to life
The behaviour of the air in the Troposphere leads to
Weather
TROPOPAUSE:
Separates the Troposphere from the Stratosphere
The atmosphere is composed of
gases , solids and Liquid and these are essential for life
on Earth
- GASES:
Troposphere is a mixture of gases
Permanent gases
Nitrogen - 78% , Oxygen - 21 % and Argon – 1%
- SOLIDS:
the minute solid dust particles and salt crystals in the air on which water
vapour condenses on.
- LIQUID:
Water in the form of clouds
the atmosphere is essential for the following reasons
- allow us to experience different weather conditions and
climate - absorb dangerous radiation from the sun
- consists of gases essential to life
Causes of Ozone depletion
human activities in the form of use aerosol sprays ,
refrigerants, air conditioners and industrial cleaners that releases (CFCs)
Effects of Ozone depletion.
- allowing the dangerous Ultraviolet rays to reaching the earth’s
surface
2.
Ways of reducing Ozone depletion
Reduce the use of products that contain CFCs and use products that do not release CFCs
Processes associated with heating of the Atmosphere:
- the sun is the main source of heat on the earth
how does the sun heat up the atmosphere
Sun radiation passes through the atmosphere and heats the earth’s surface and it
absorbs the heat and in turn heats up the atmosphere.
The sun’s electromagnetic spectrum-
the distribution of the sun’s radiation according to
wavelength.
Radiant energy is transmitted in the form of
waves of different wavelengths
types of rays that are radiated from the sun
the infra-red waves with longer
wavelength , the X-rays with shorter rays ultraviolet rays and the light rays
Insolation
incoming solar radiation
Most of the ultraviolet and X-rays are absorbed in the
thermosphere and stratosphere
SOLAR CONSTANT
the radiant energy that reaches the troposphere
53% of the sun’s radiation that reaches the troposphere does not reach the earth’s
surface due to:
Reflection of the radiation from surfaces before it is absorbed due to different
properties of reflection
Gases in the troposphere absorb some of the radiation through ABSORPTION
Some radiation is bounced off dust particles - SCATTERING
The energy that reaches the earth’s surface is in the form of
short wave radiation
which is not absorbed by the atmosphere and is the energy that heats the earth’s
surface
Terrestrial radiation
all heat from the earth
The water vapour and gases (carbon dioxide) absorb the
long wave terrestrial
radiation
Water vapour and carbon dioxide are close to the surface hence
more absorption
takes place thus the reason why the air is warmer.
Terrestrial radiation mainly happens at
night
Cand clouds act as a blanket to
prevent
terrestrial radiation from escaping to the atmosphere
Conduction
transfer of heat from one air molecule to another by contact
Convection
Vertical transfer of heat energy by movement of air molecules.
Release of latent heat:
- Heat can also be transferred when condensation takes place
